JPH0636909Y2 - Foaming furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a foaming furnace for foaming a thermoplastic resin plate-shaped molded product having a foaming ability.

[Conventional technology of the invention]

Conventionally, as a foaming furnace for foaming continuously supplied thermoplastic resin sheets having a foaming ability, for example, Japanese Patent Publication
As shown in Japanese Patent Laid-Open No. 42-18832, there is known a foaming furnace which foams a sheet while vertically descending it.

[Problems to be solved by the invention]

However, in the conventional foaming furnace, although the hot air exhaust pipe is provided at the upper part, a part of the hot air blows out from the vicinity of the inlet where the sheet is introduced into the foaming furnace, but the hot air amount becomes unbalanced on both sides of the sheet. The seat can be lifted,
The hot and cold parts were formed near the upper corner of the furnace, which sometimes affected the foaming result.

[Means for solving problems]

The foaming furnace of the present invention is a foaming furnace in which a thermoplastic resin sheet having a foaming ability is continuously lowered in the vertical direction to foam, and a narrow portion is formed at the upper end of the foaming furnace, and the narrow portion is formed. Exhaust ducts are provided on both sides along the width direction of the sheet through a perforated partition plate, exhaust ports are provided at both ends of the exhaust duct, and inclined guide walls are provided at corners below the narrow portion of the foaming furnace. It is characterized by that.

[Action]

The present invention uses a well-designed configuration to equalize the temperature inside the furnace,
Stable foaming can be achieved by reducing hot air retention and overflow.

〔Example〕

Next, an example of the foaming furnace of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a thermoplastic resin sheet having a foaming ability, which has been preheated in a preheating chamber (not shown), and passes through an upper inlet 21 of a square tower-shaped foaming furnace 2 having a heat insulating wall, and inside the foaming furnace 2. Is continuously transferred vertically downward to the heater, and is heated uniformly to a foaming temperature or higher by the hot air blown from the heater 3 equipped with a far infrared heater or the like and the air supply port 4 to be foamed to a desired ratio, and the lower outlet. It is transferred to the outside of the foaming furnace 2 through 22.

The hot air blown out from the air supply port 4 rises to the upper end of the foaming furnace 2 by the inclined guide wall 23 without staying in the corners, and a narrow portion at the upper end of the foaming furnace 2 and a hole in the narrow portion. By the partition plate 51, the exhaust ducts 5 provided on both sides along the width direction of the seat 1 uniformly inhale an appropriate amount of hot air in the narrow portion and to the outside from the exhaust ports 6 at both ends of the exhaust duct 5. Discharge.

The discharged hot air is circulated through an air heating device (not shown).

[Effect of device]

According to the present invention, the inclined guide wall, the narrow portion at the upper end of the foaming furnace, and the exhaust duct allow hot air to stay in the corners, rise unbalancedly at the upper end of the foaming furnace, and overflow. It is possible to efficiently produce a high-quality foam without stabilizing the homogenization of the temperature inside the furnace and stabilizing the foaming conditions.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention. 1 ... Thermoplastic resin sheet, 2 ... Foaming furnace, 21 ... Inlet, 22 ... Exit, 23 ... Inclined guide wall, 3 ... Heater, 4
…… Air supply port, 5 …… Exhaust duct, 51 …… Perforated partition plate, 6
……exhaust port

Claims (1)

[Scope of utility model registration request] 1. In a foaming furnace in which a thermoplastic resin sheet having a foaming ability is continuously lowered in a vertical direction to foam, a narrow portion is formed at an upper end of the foaming furnace, and the narrow portion is provided. Exhaust ducts are provided on both sides along the width direction of the sheet via a hole partition plate, exhaust ports are provided at both ends of the exhaust duct, and an inclined guide wall is provided at a corner portion below the narrow portion of the foaming furnace. A foaming furnace characterized by that.